Lemongrass (Cymbopogon citratus)-incorporated chitosan bioactive films for potential skincare applications

Circular economy, and concerns about environmental waste, is fostering the development of sustainable alternative products in a range of industries. In the dermo-cosmetic field, the market for sustainable anti-aging skincare products has increasingly grown over the last years. The innovation of this work was to develop chitosan films incorporating lemongrass essential oil (LEO) that could potentially be applied as a green cosmetic skin treatment due to their anti-oxidant and antimicrobial properties, using renewable and biodegradable materials. Different concentrations of LEO (i.e., 0.5, 1.0, and 1.5 % w/w) were formulated into chitosan filmogenic matrices, forming skincare bioactive films. Their antioxidant properties and water vapor permeability were strongly governed by the LEO concentration. Chitosan bioactive films containing 0.5 % LEO showed cellular viability over 70 %, while those with 1.5 % LEO had similar antioxidant capacity as NAC (N-acetyl-L-cysteine), used as the positive control to inactivate intracellular reactive oxygen species (ROS) in HaCat cells not treated with H₂O₂. The developed bioactive films showed activity against Escherichia coli and Staphylococcus aureus. Our LEO-loaded chitosan biofilms may be used as sheet masks with antioxidant and antimicrobial properties for skincare, with high flexibility and selected permeability, and without cytotoxic risks.